Waterproof slide fastener and method of producing the same

ABSTRACT

An interconnection sheet is arranged which is separate to a rear stop. At least one second securement hole in at least one of left and right waterproof tapes is not covered by the interconnection sheet, and a rear stop is arranged to fill the at least one second securement hole.

TECHNICAL FIELD

The present disclosure relates to waterproof slide fastener and method of producing the same.

BACKGROUND ART

Waterproof slide fasteners require multiple production processes compared with non-waterproof slide fasteners, and its higher cost of production might be problematic. In past, as seen in FIG. 4 of patent literature 1, a sheet member is laminated onto a bottom surface of a fastener tape (particularly onto its waterproof layer) by using a technique of high frequency welding, followed by a through hole formed that penetrates the fastener tape and the sheet member, and followed by a stop member formed through injection molding at a place where the through hold is formed.

Unlike the above-described method, patent literature 2 discloses an injection molding through which a stop member is formed in which sheet member is incorporated/integrated. In more detail, a stop member is disclosed which has a main body for stopping a slider and an extension extending from the main body. This literature discloses that fist through-holes are formed for fastener elements and second through-holes are formed for the stop member (See FIG. 3 of the same literature).

Patent literature 3 also discloses an injection molding through which a stop member is formed in which a sheet member is incorporated/integrated (See FIG. 6 and para. 0042 of the same literature).

CITATION LIST Patent Literature

-   [Patent literature 1] Japanese Patent Application Laid-open No.     2007-215819 -   [Patent literature 2] International Publication No. 2013/114529 -   [Patent literature 3] International Publication No. 2019/180758

SUMMARY Technical Problem

In cases where an interconnection sheet is laminated onto left and right fastener tapes to join the left and right fastener tapes, a process of perforation would be required after the process of lamination to form a hole so as to allow melted plastic to flow between the upper and lower cavities for injection molding of rear stop (i.e. a hole penetrating through the fastener tape and the interconnection sheet (see FIG. 4 of the patent literature 1)). This holds true to cases where there remains holes, formed for injection molding of fastener elements, in the fastener tape. Because, the holes would be closed by the sheet member when the sheet member is laminated. Such a process of perforation triggered by the lamination of the sheet member has been found to be a cause of increased cost of waterproof slide fasteners.

Solution to Problem

Waterproof slide fastener according to an aspect of the present disclosure may include: left and right fastener stringers including left and right waterproof tapes and left and right rows of fastener elements where fastener elements are arranged, the left and right rows of fastener elements secured to side-edges of the left and right waterproof tapes, and each of the left and right waterproof tapes including a row of securement holes including a linear arrangement of securement holes at a predetermined pitch; an interconnection sheet that joins the left and right waterproof tapes in a rear end of the waterproof slide fastener; and a rear stop arranged at a rear contiguous position of the left and right rows of fastener elements. The row of securement holes in each of the left and right waterproof tapes includes a multiplicity of first securement holes and one or plural second securement holes arranged on a side of the rear stop relative to the multiplicity of first securement holes, respective ones of the first securement holes filled by respective ones of the fastener elements. The interconnection sheet is arranged to expose at least one second securement hole in at least one of the left and right waterproof tapes, and the rear stop is arranged to fill said at least one second securement hole.

In some embodiments, the rear stop includes an upper portion and a lower portion which are arranged at upper and lower sides of the left and right waterproof tapes, and the upper portion and the lower portion are interconnected one another via a plurality of plugs only, the plurality of plugs respectively filling the one or plural second securement holes in both of the left and right waterproof tapes. Pinhole may be formed in the lower portion of the rear stop, the pinhole extending to reach the interconnection sheet

In some embodiments, a recess or a cutout is formed in the interconnection sheet to expose the one or plural second securement holes in at least one of the left and right waterproof tapes. The recess or the cutout may be fully filled by the rear stop. The recess or the cutout may be formed not to cross a boundary between the left and right waterproof tapes in a closed condition of the left and right fastener stringers.

In some embodiments, the one or plural second securement holes are positioned at a rearmost position in the row of securement holes. Number of the second securement hole in each one of the left and right waterproof tapes may be one. The rear stop may be configured to enclose, at least partially, left and right fastener elements positioned at the rear end of the left and right rows of fastener elements. Gate mark may be formed on the interconnection sheet. Another gate mark different from the one formed on the interconnection sheet may be formed on the rear stop.

A method of producing a waterproof slide fastener according to another aspect of the present disclosure includes: producing a fastener stringer wherein a row of fastener element where fastener elements are arranged is secured to a side-edge of a waterproof tape; forming an interconnection sheet onto a fastener chain including a pair of the fastener stringers; and forming a rear stop onto the fastener chain through injection molding. Rows of securement holes each of which including a linear arrangement of securement holes at a predetermined pitch are formed in the respective ones of left and right waterproof tapes. The respective rows of securement holes include a multiplicity of first securement holes and one or plural second securement holes arranged on a side of the rear stop relative to the multiplicity of first securement holes. The interconnection sheet is formed through injection molding to expose at least one second securement hole in at least one of the left and right waterproof tapes. The rear stop is formed through injection molding to fill said at least one second securement hole.

In some embodiments, the rear stop includes an upper portion and a lower portion which are arranged at upper and lower sides of the left and right waterproof tapes, and the upper portion and the lower portion are interconnected one another via a plurality of plugs only, the plurality of plugs respectively filling the one or plural second securement holes in both of the left and right waterproof tapes.

In some embodiments, a recess or a cutout is formed in the interconnection sheet to expose the one or plural second securement holes in at least one of the left and right waterproof tapes.

Advantageous Effects of Invention

According to an aspect of the present disclosure, even in cases where the interconnection sheet is provided prior to the rear stop is provided, process of perforation conducted for injection molding of the rear stop would be omitted or a number of the through-hole would be reduced even when such perforation process were conducted, thus facilitating cost-reduced waterproof slide fasteners.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic top view of a waterproof slide fastener according to an aspect of the present disclosure.

FIG. 2 is a schematic bottom view illustrating a rear end of the waterproof slide fastener.

FIG. 3 is a schematic partial top view of a left fastener stringer, dash circles denote securement holes formed at a constant pitch in the fastener tape.

FIG. 4 is a schematic cross-sectional view taken along an alternate long and short dash line IV-IV in FIG. 3 .

FIG. 5 is a schematic bottom view of the rear end of the slide fastener, schematically illustrating a relationship among first and second securement holes, an interconnection sheet and a rear stop.

FIG. 6 is a schematic cross-sectional view taken along an alternate long and short dash line VI-VI in FIG. 5 .

FIG. 7 is a schematic cross-sectional view taken along an alternate long and short dash line VII-VII in FIG. 5 .

FIG. 8 is a schematic cross-sectional view taken along an alternate long and short dash line VIII-VIII in FIG. 5 .

FIG. 9 is a production process diagram of a waterproof tape, illustrating a process of extrusion.

FIG. 10 illustrates a process of perforation for forming a row of securement holes.

FIG. 11 illustrates a process of injection molding to form the fastener elements.

FIG. 12 illustrates a process of injection molding of the interconnection sheet.

FIG. 13 illustrates a process of injection molding of the rear stop.

FIG. 14 is a reference diagram illustrating a state in which the fastener elements are formed.

FIG. 15 is a reference diagram illustrating a state in which the interconnection sheet is formed.

FIG. 16 is a reference diagram illustrating a state in which the rear stop is formed.

FIG. 17 is a schematic view of a modified example of interconnection sheet.

FIG. 18 is a schematic view of a modified example of interconnection sheet.

FIG. 19 is a schematic view of a modified example of interconnection sheet.

FIG. 20 is a schematic view of a modified example regarding rows of securement holes.

DESCRIPTION OF EMBODIMENTS

Hereinafter, various embodiments and features will be described with reference to drawings. A skilled person in the art would be able to combine respective embodiments and/or respective features without requiring excess descriptions, and would appreciate synergistic effects of such combinations. Overlapping descriptions among the embodiments are basically omitted. Referenced drawings aim mainly for describing inventions and are simplified for the sake of convenience of illustration. The respective features should be appreciated as universal features not only effective to waterproof slide fasteners and methods of producing the same presently disclosed but also effective to other various waterproof slide fasteners and methods of producing the same not disclosed in the present specification.

Hereinafter, front-rear direction would be understood based on a direction of movement of slider. Left-right direction is orthogonal to the front-rear direction and parallel to a plane in which fastener tapes exist. Up-down direction is orthogonal to the front-rear and left-right directions. The directions defined here might be redefined differently in light of the following descriptions.

As shown in FIGS. 1 and 2 , a waterproof slide fastener 1 (hereinafter simply referred to as a slide fastener 1) is a belt-like member elongated in the front-rear direction and having a narrow width in the left-right direction, and attached to an opening in garments or bags so as to open or close the opening. Normally, there would be no chance for water to flow into the inside via the slide fastener 1 when the slide fastener 1 is closed, because the slide fastener 1 is waterproof. The slide fasteners 1 are typically attached to the opening of garments or bags by a process such as thermal pressure bonding, thermal welding or sewing.

The slide fastener 1 has left and right fastener stringers 61 and 62 in which left and right rows 20 and 30 of fastener elements are secured onto side-edges 41 and 51 of the left and right waterproof tapes 40 and 50; and a slider 11 that moves frontward to engage the left and right fastener elements 21 and 31 of the left and right rows 20 and 30 of fastener elements and moves rearward to disengage the left and right fastener elements 21 and 31.

The slider 11 is made of plastic or metal, and has a top wing, a bottom wing, and a coupling pillar coupling these wings. The slider 11 would be one which is normally employed and thus further detail descriptions of its configuration would be omitted. As the slider 11 moves frontward and the slide fastener 1 is closed, the side-edges 41,51 of the left and right waterproof tapes 40,50 are brought into pressure contact with one another, ensuring the waterproofness of slide fastener 1.

Front stop 12 is arranged at a front end of the slide fastener 1 (a position frontward of and adjacent to the left and right rows 20, 30 of fastener elements). Rear stop 80 is arranged at a rear end of the slide fastener 1 (at a rear contiguous position of the left and right rows 20 and 30 of fastener elements). The front stop 12 and the rear stop 80 are formed by injection molding of thermoplastic plastic material (e.g. polyacetal, polyamide, polypropylene, polybutylene terephthalate, nylon, or polycarbonate). The front stop may be configured as disclosed in the patent literature 3, for example. The configuration of the rear stop 80 would be discussed below. The front and rear stops 12 and 80 serve not only to block the movement of slider 11 but also to ensure the waterproofness by joining the left and right waterproof tapes 40 and 50.

The waterproof tape 40, 50 includes a tape main portion 42,52 with upper and lower surfaces in which embossed patterns are formed (See FIG. 3 ). The side-edge 41, 51 is positioned inwardly of the left-right direction of the tape main portions 42, 52. The waterproof tape 40, 50 has a tape base fabric 43 covered by a waterproof layer 44 (See FIG. 4 ). The tape base fabric 43 is formed to be a woven or knitted structure or mixed structure of the two. The waterproof layer 44 is formed to cover the tape base fabric 43, thus allowing waterproofness. The waterproof layer 44 may be made of thermoplastic elastomer, for example.

In the respective ones of the left and right waterproof tapes 40,50, a row 90 of securement holes is formed in which securement holes 91,92 are linearly arranged at a predetermined pitch P1 (See FIGS. 3 and 5 ). Each of the rows 90 of securement holes includes a multiplicity of first securement holes 91 (See FIG. 3 ) where the first securement holes 91 are filled by the fastener elements 21, 31 respectively. Furthermore, each of the rows 90 of securement holes includes one or plural second securement holes 92 (See FIG. 5 ) arranged on a side of the rear stop 80 relative to the multiplicity of first securement holes 91. The first securement holes 91 are formed for the fastener elements respectively, and the second securement holes 92 are formed for the rear stop 80. Therefore, the number of the first securement hole 91 is greater than the number of the second securement holes 92. The first and second securement holes 91 and 92 have a same aperture shape and a same aperture diameter. Typically, the second securement hole is positioned at the rearmost end of the row of securement holes and/or the number of the second securement hole is one.

The fastener elements 21 and 31 are formed by injection molding of thermoplastic plastic material (e.g. polyacetal, polyamide, polypropylene, polybutylene terephthalate, nylon, or polycarbonate), and the first securement holes 91 are filled by the plastic material. The fastener element 21,31 adheres to the waterproof tape 40,50 and would not rotate easily about the first securement hole 91. The respective ones of fastener elements are arranged corresponding to the respective ones of the first securement holes. Therefore, in each of the rows 20, 30 of fastener elements, the fastener elements 21,31 are arranged at a predetermined pitch P1 which is equal to the pitch of the securement holes 91, 92.

The fastener element 21,31 has a base portion 22, a head 23, and a neck 24 interposed between the base portion 22 and the head 23 (See FIG. 3 ). Groove 21 j extending in the front-rear direction is formed in the end face of the head 23, and the (inward) edge of the waterproof tape 40,50 (in the left-right direction) is arranged to protrude from the bottom of the groove 21 j (See FIG. 4 ). Furthermore, the fastener element 21,31 has a shoulder 25 having a thinner thickness arranged at the both sides of the neck 24 in the front-rear direction, and fins 26 having a thinner thickness and extending from the base portion 22 outward of the left-right direction. The shoulder 25 is inserted into the groove 21 j of the head 23 of the cooperating fastener element for engagement. The fins 26 are inserted into a space between upper and lower flanges (not illustrated) of the slider 11.

When the slide fastener 1 is closed, the head 23 of the fastener element 21 is sandwiched between the heads of adjacent fastener elements 31 at front and rear sides. Similarly, the head of the fastener element 31 is sandwiched between the heads 23 of adjacent fastener elements 21 at front and rear sides. The left and right fastener elements 21, 31 are engaged as such, allowing the side edge 41 c of the waterproof tape 40 and the side edge of the waterproof tape 50 being brought into pressure contact. These side edges may be referred to as tape-joining side edges.

The fastener element 21,31 has element upper and lower portions 27 and 28 arranged at upper and lower sides of the waterproof tape 40,50, and a plug 29 filling the first securement hole 91 (See FIG. 4 ). The element upper and lower portions 27 and 28 are interconnected one another via only one plug 29. Note that the element upper portion 27 includes upper halves of the head, the neck and the base portion. Similarly, the element lower portion 28 includes lower halves of the head, the neck and the base portion.

Configuration of the rear end of the slide fastener 1 will be described with reference to FIGS. 5-8 . In addition to the rear stop 80, an interconnection sheet 70 is arranged in the rear end of the slide fastener 1 (positioned rearward of and adjacent to the left and right rows 20, 30 of fastener elements). The interconnection sheet 70 is made of plastic material (e.g. thermoplastic plastic such as polyacetal, polyamide, polypropylene, polybutylene terephthalate, nylon, or polycarbonate) which is the same or different material as the material of the rear stop 80. Suitable material could be selected for the plastic material of the interconnection sheet 70 which enables deformation (e.g. bending or flexing) of the interconnection sheet 70 following the waterproof tape. By suitably selecting material, the interconnection sheet 70 could have a moderate degree of softness. In some cases, the softness of the interconnection sheet 70 is greater than that of the rear stop 80, but should not necessarily be limited to this. The interconnection sheet 70 is arranged to cross the boundary B1 between the left and right waterproof tapes 40 and 50 and to cover the lower surfaces of the left and right waterproof tapes 40 and 50.

Suitable material would be selected for the plastic material of the rear stop 80 which could endure repeating collisions or contacts with the slider 11. By appropriately selecting material, the rear stop 80 could have sufficient hardness and mechanical strength. In some cases, the hardness or mechanical strength of the rear stop 80 is greater than that of the interconnection sheet 70, but should not necessarily be limited to this. Embodiments are envisaged where the softness of the rear stop 80 is equal to or higher than that of the interconnection sheet 70.

The rear stop 80 includes upper and lower portions 81 and 82 arranged at upper and lower sides of the left and right waterproof tapes 40 and 50. The upper portion 81 and the lower portion 82 are interconnected one another by a plurality of plugs 83 by which one or plural second securement holes 92 in the left and right waterproof tapes 40 and 50 are filled. The rear stop 80 is configured to enclose at least partially the left and right fastener elements 21, 31 positioned at the rear end of the left and right rows 20 and 30 of fastener elements. This may suppress the exposure of the tape-joining side edges of the left and right fastener tapes. The lower portion 82 of the rear stop 80 covers the interconnection sheet 70, and there is no gap between the rear stop 80 and the interconnection sheet 70.

The interconnection sheet 70 and the rear stop 80 are formed separately or by two-steps of injection molding, allowing use of different suitable material for the interconnection sheet 70 and the rear stop 80 as discussed above. Furthermore, separate gate marks are formed between the interconnection sheet 70 and the rear stop 80. Note that a gate mark is formed by cutting a solidified plastic between a mold cavity and a gate. Treatment (such as polishing) to make the gate mark less visible might be applicable. In cases where the interconnection sheet 70 is laminated to the waterproof tape by the use of high frequency welding technique, the second securement hole 92 may possibly be closed by the interconnection sheet 70, depending to a position of the interconnection sheet 70. In cases where the interconnection sheet 70 is formed by injection molding, the unintentional closure of the second securement hole 92 would be avoided or suppressed by its positioning in the mold.

It might be possible to laminate the interconnection sheet 70 onto the waterproof tape by using the high frequency welding technique as long as it is ensured that the second securement hole 92 is not covered by the interconnection sheet 70. However, there is a possibility that a longer time is needed for a purpose of positioning the interconnection sheet 70 on the fastener chain. Furthermore, when manufacturing and storing interconnection sheets 70 of predetermined size, the interconnection sheets 70 may possibly shrink and change in its size. Moreover, even assuming cases where the interconnection sheet 70 with a recess were to be produced, it might change in its shape when melting and adhering, and might result in its unintentional deformation, making it more difficult to adhere the interconnection sheet 70 as intended. Furthermore, there would be a burden of education for factory workers in charge of production as high frequency welding requires expertise and experience of managing and operating a high frequency power source.

In the present embodiment, the interconnection sheet 70 is arranged to expose at least one second securement hole 92 in at least one of the left and right waterproof tapes 40 and 50, and the rear stop 80 is arranged to fill the at least one second securement holes 92. According to this feature, even in cases where the interconnection sheet 70 is formed separately from the rear stop 80, a securement hole, which is a part of the row 90 of securement holes, could be allocated as the second securement hole 92 for the rear stop 80, thus omitting the process of perforation performed for the rear stop 80 or reducing the number of through-hole even if the process of perforation be performed.

Recess or cutout 76 may be formed in the interconnection sheet 70 to expose the at least one second securement hole 92 in at least one of the left and right waterproof tapes 40 and 50 (See FIG. 5 ). The interconnection sheet 70 can be positioned as close as possible to the rows 20 and 30 of fastener elements, reducing possibility of water leak through the boundary B1 between the waterproof tapes 40 and 50 in a location between the interconnection sheet 70 and the left and right rows 20 and 30 of fastener elements.

The recess or cutout 76 is fully filled by the rear stop 80 (the plastic material of the rear stop 80) and does not appear on the exterior of the slide fastener 1. The rear stop 80 has a filling portion 84 that fills the recess or cutout 76, and the filling portion 84 is connected to the plug 83 filling the second securement hole 92 (See FIG. 6 ). Note that, there may be concern of induced water leak if the recess or cutout 76 were exposed outside of the rear stop 80.

The recess or cutout 76 is formed not to cross the boundary B1 between the left and right waterproof tapes 40 and 50 in a closed condition of the left and right fastener stringers 61 and 62. This allows reduced possibility of water leak through the boundary B1 otherwise caused when the recess or cutout 76 were arranged on the boundary B1.

Pinhole 85 is formed in the lower portion 82 of the rear stop 80 which extends to reach the waterproof tape 40, 50 or the interconnection sheet 70. Optionally, a pinhole 85 is formed in the upper portion 81 of the rear stop 80 which extends to reach the waterproof tape 40,50. This suppresses flapping of the waterproof tapes 40, 50 during the injection molding of the rear stop 80.

Note that, it would be possible to form a through-hole penetrating through the laminate of the waterproof tape 40, 50 and the interconnection sheet 70 after formation of the interconnection sheet 70 and to use it as a cavity communication channel for injection molding of the rear stop 80. Even in this case, the number of newly formed through-hole would be reduced owing to the second securement hole 92 not covered by the interconnection sheet 70, thus facilitating minimized and cost-reduced perforation tool.

Hereinafter, a method of producing slide fasteners 1 will be described with reference to FIGS. 9-16 . Firstly, a waterproof tape is produced by extrusion as shown in FIG. 9 . Specifically, a tape base fabric 43 is supplied to a mold 101, and the upper and lower surfaces and the side edge 41 c of the tape base fabric 43 are covered by melted elastomer filling a supply channel in the mold 101. The elastomer cures to be the waterproof layer 44.

Next, the waterproof tape is perforated as shown in FIG. 10 . Specifically, the waterproof tape is supplied directly under perforation punches 102, and the perforation punches 102 are moved down to form the first and second securement holes 91 and 92. The waterproof tape is sandwiched between a pressure roll 104 and a driving roll 105 and transferred downstream in accordance with rotation of the driving roll 105. The downward motion of the perforation punches 102 is in synchronization with a downstream transfer of a predetermined length of the waterproof tape, allowing the securement holes be formed at a predetermined pitch P1. For a purpose of stable perforation, a stage 103 may be employed in which cylindrical holes are arranged into which the punches 102 are inserted respectively. Waste fragments caused by the piercing will be collected by a box located beneath the stage 103.

Next, the fastener elements are formed through injection molding as shown in FIG. 11 . Specifically, the waterproof tape with the first and second securement holes 91 and 92 is interposed between a lower mold 106 and an upper mold 107, and melted plastic is supplied into a mold cavity 108 defined by the molds 106 and 107 through a channel (sprue, runner and gate) to form the fastener elements. The lower and upper molds 106 and 107 are cooled, allowing the melted plastic in the mold cavity 108 be solidified. As such, the fastener elements filling the first securement holes 91 and the fastener stringer with such fastener elements arranged at a predetermined pitch are produced.

Next, the lower and upper molds 111 and 112 shown in FIG. 12 are used to produce the interconnection sheet 70 through injection molding. Specifically, the fastener stringers produced as described above are engaged to be a fastener chain, and the chain is arranged in a recess on the top surface of the lower mold 111. The upper mold 112 is stacked onto the lower mold 111, defining a mold cavity 70′ for molding the interconnection sheet 70. Melted plastic is supplied to the mold cavity 70′ via a channel (sprue, runner and gate), and the lower and upper molds 111 and 112 are cooled and thus the interconnection sheet 70 is formed. The interconnection sheet 70 is formed through injection molding, more reliably preventing the second securement hole 92 from being closed by the interconnection sheet 70.

Next, the lower and upper molds 113 and 114 shown in FIG. 13 are used to produce the rear stop 80 through injection molding. Specifically, the fastener chain in which the left and right fastener stringers are coupled by the interconnection sheet 70 is arranged in a recess on the top surface of the lower mold 113. The upper mold 114 is stacked onto the lower mold 113, defining a mold cavity 80′ for molding the rear stop 80. Melted plastic is supplied to the mold cavity 80′ via a channel (sprue, runner and gate), and the lower and upper molds 113 and 114 are cooled, thus forming the rear stop 80.

The mold cavity 80′ includes a first space 81′ in which the upper portion 81 of the rear stop 80 is molded and a second space 82′ in which the lower portion 82 of the rear stop 80 is molded. These first and second spaces 81′ and 82′ are in spatial communication via the second securement hole(s) 92 (functioning as cavity communication channel). Therefore, the melted plastic can communicate between the first and second spaces via the second securement hole(s) 92 even a gate provided on only one of the lower and upper molds.

As described above, the interconnection sheet is formed through injection molding to join the left and right waterproof tapes 40 and 50 in the fastener chain (see FIGS. 14 and 15 ). The interconnection sheet 70 is formed not to close the respective second securement holes 92 in the left and right waterproof tapes 40 and 50. Therefore, a process of perforation to form a through-hole penetrating through the waterproof tape and the interconnection sheet could be omitted, or the number of through-hole could be reduced even if such a process of perforation were conducted.

As described above, the rear stop 80 is formed through injection molding, and the rear stop 80 is formed to enclose at least partially the left and right fastener elements 21 and 31 positioned at the rear end of the left and right rows 20 and 30 of fastener elements (see FIG. 16 ). Further, the lower portion 82 of the rear stop 80 is formed to cover the front end portion of the interconnection sheet 70. Still further, a pinhole 85 extending to reach the interconnection sheet 70 is formed in the lower portion 82 of the rear stop 80.

Hereinafter, variants of the presently disclosed features will be described. A cutout 76 may be formed in the interconnection sheet 70 as shown in FIG. 17 . Similar technical effects as discussed above would be achieved even in such an embodiment. The cutout 76 is shaped to form a step at the front edge of the interconnection sheet 70. The cutout 76 does not cross the boundary B1 between the left and right waterproof tapes 40 and 50, ensuring firmer joining of the left and right waterproof tapes 40 and 50.

The cutout 76 may be formed in the interconnection sheet 70 as shown in FIG. 18 . Similar technical effects as discussed above would be achieved even in such an embodiment. The cutout 76 is shaped to form a V-groove at the front edge of the interconnection sheet 70. The cutout 76 crosses the boundary B1 between the left and right waterproof tapes 40 and 50, but is fully filled by the rear stop 80. Therefore, a given level of waterproofness of the waterproof tapes 40 and 50 would be ensured.

In a case shown in FIG. 19 , one securement hole 92′, which is used as the second securement hole 92 in the above embodiments, is closed by the interconnection sheet 70. The rear stop 80 is arranged to fill just one second securement hole 92.

In a case shown in FIG. 20 , the interconnection sheet 70 is formed to cover or fill third securement holes 93 which are different from the first and second securement holes in the rows of securement holes. It should be noted that redundant perforation of the waterproof tape 40, 50 may be undesirable as possibly leading to deteriorated waterproofness.

A skilled person in the art would be able to add various modifications to the respective embodiments based on the above teachings. Reference codes in Claims are added just for a purpose of reference and should not be referred to for narrowly construing the scope of Claim.

LIST OF REFERENCE NUMERALS

-   -   1 Waterproof slide fastener     -   20,30 Row of fastener elements     -   21,31 Fastener element     -   40,50 Waterproof tape     -   61,62 Fastener stringer     -   70 Interconnection sheet     -   80 Rear stop     -   81 Upper portion     -   82 Lower portion     -   83 Plug     -   90 Row of securement holes     -   91 First securement hole     -   92 Second securement hole 

1. A waterproof slide fastener comprising: left and right fastener stringers including left and right waterproof tapes and left and right rows of fastener elements where fastener elements are arranged, the left and right rows of fastener elements secured to side-edges of the left and right waterproof tapes, and each of the left and right waterproof tapes including a row of securement holes including a linear arrangement of securement holes at a predetermined pitch; an interconnection sheet that joins the left and right waterproof tapes in a rear end of the waterproof slide fastener; and a rear stop arranged at a rear contiguous position of the left and right rows of fastener elements, wherein the row of securement holes in each of the left and right waterproof tapes includes a multiplicity of first securement holes and one or plural second securement holes arranged on a side of the rear stop relative to the multiplicity of first securement holes, respective ones of the first securement holes filled by respective ones of the fastener elements, and wherein the interconnection sheet is arranged to expose at least one second securement hole of said one or plural second securement holes in at least one of the left and right waterproof tapes, and the rear stop is arranged to fill said at least one second securement hole.
 2. The waterproof slide fastener of claim 1, wherein the rear stop includes an upper portion and a lower portion which are arranged at upper and lower sides of the left and right waterproof tapes, and the upper portion and the lower portion are interconnected one another via a plurality of plugs only, the plurality of plugs respectively filling the one or plural second securement holes in both of the left and right waterproof tapes.
 3. The waterproof slide fastener of claim 2, wherein a pinhole is formed in the lower portion of the rear stop, the pinhole extending to reach the interconnection sheet.
 4. The waterproof slide fastener of claim 1, wherein a recess or a cutout is formed in the interconnection sheet to expose the one or plural second securement holes in at least one of the left and right waterproof tapes.
 5. The waterproof slide fastener of claim 4, wherein the recess or the cutout is fully filled by the rear stop.
 6. The waterproof slide fastener of claim 4, wherein the recess or the cutout is formed not to cross a boundary between the left and right waterproof tapes in a closed condition of the left and right fastener stringers.
 7. The waterproof slide fastener of claim 1, wherein the one or plural second securement holes are positioned at a rearmost position in the row of securement holes.
 8. The waterproof slide fastener of claim 1, wherein a number of the second securement hole in each one of the left and right waterproof tapes is one.
 9. The waterproof slide fastener of claim 1, wherein the rear stop is configured to enclose, at least partially, left and right fastener elements positioned at the rear end of the left and right rows of fastener elements.
 10. The waterproof slide fastener of claim 1, wherein a gate mark is formed on the interconnection sheet.
 11. The waterproof slide fastener of claim 10, wherein another gate mark different from the one formed on the interconnection sheet is formed on the rear stop.
 12. A method of producing a waterproof slide fastener, the method including: producing a fastener stringer wherein a row of fastener element where fastener elements are arranged is secured to a side-edge of a waterproof tape; forming an interconnection sheet onto a fastener chain including a pair of the fastener stringers; and forming a rear stop onto the fastener chain through injection molding, wherein rows of securement holes each of which including a linear arrangement of securement holes (91,92) at a predetermined pitch are formed in the respective ones of left and right waterproof tapes, the respective rows of securement holes include a multiplicity of first securement holes and one or plural second securement holes arranged on a side of the rear stop relative to the multiplicity of first securement holes, the interconnection sheet is formed through injection molding to expose at least one second securement hole in at least one of the left and right waterproof tapes and, the rear stop is formed through injection molding to fill said at least one second securement hole.
 13. The method of producing a waterproof slide fastener of claim 12, wherein the rear stop includes an upper portion and a lower portion which are arranged at upper and lower sides of the left and right waterproof tapes, and the upper portion and the lower portion are interconnected one another via a plurality of plugs only, the plurality of plugs respectively filling the one or plural second securement holes in both of the left and right waterproof tapes.
 14. The method of producing a waterproof slide fastener of claim 12, wherein a recess or a cutout is formed in the interconnection sheet to expose the one or plural second securement holes in at least one of the left and right waterproof tapes.
 15. The waterproof slide fastener of claim 1, wherein the rear stop includes: an upper portion; a lower portion; and a plurality of plugs by which the upper and lower portions are interconnected, wherein the plurality of plugs includes one or more first plugs filling said one or plural second securement holes in the left waterproof tape, and one or more second plugs filling said one or plural second securement holes in the right waterproof tape.
 16. The waterproof slide fastener of claim 15, wherein the interconnection sheet is shaped to have a recess or a cutout that overlaps said at least one second securement hole.
 17. The waterproof slide fastener of claim 16, wherein the one or plural second securement holes are positioned at a rearmost position in the row of securement holes.
 18. The waterproof slide fastener of claim 17, wherein a number of the second securement hole in each one of the left and right waterproof tapes is one.
 19. The waterproof slide fastener of claim 17, wherein the rear stop is configured to enclose, at least partially, left and right fastener elements positioned at the rear end of the left and right rows of fastener elements.
 20. The waterproof slide fastener of claim 17, wherein a first gate mark is formed on the interconnection sheet, and a second gate mark is formed on the rear stop. 